Boris the Animal, the monstrous villain of Men in Black III, had some creepy touches, including the weird teeth and the spidery things coming out of the palms of his hands. But he could have looked a lot nastier, judging from this early concept art by Kevin Chen, based on designs by superstar creature designer Rick Baker.

Also from Chen: this early piece of concept for the alien fish that the Men in Black face early on in the film: